GaydemonEpubDownloadHelper.user.js

// ==UserScript==
// @name         gaydemon epub download helper
// @namespace    botmtl
// @version      0.2
// @description  add download epub button on story list page
// @author       botmtl
// @updateurl    https://gist.githubusercontent.com/botmtl/7574c74e7c1badd868a4d7ebfdc80033/raw/697398c3f1dab4829625cc2090c70d33d69db8c1/GaydemonEpubDownloadHelper.user.js
// @icon         http://www.gaydemon.com/apple-touch-icon-precomposed.png
// @match        http://www.gaydemon.com/stories/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    var t = document.querySelectorAll('h3 a');

    for(var i=0; i<t.length; i++) {
        var href = t[i].href;
        var storynumber = href.match(/(\d{4,7})\.html/)[1];
        var container = document.createElement("span");
        container.style="margin-left:50px;";
        container.innerHTML = '<a class="btn btn-primary btn-small" href="http://www.gaydemon.com/stories/epub/' + storynumber + '">EPUB</a>';
        t[i].appendChild(container);
    }
})();